1. Field of the Invention
The present invention relates to a device for connecting two ends of high-pressure pipelines for use in longwalls of underground mining, having a removable pipe coupling for tension-proof and tight connection of the two pipe ends, whose constructions are tailored to one another.
High-pressure pipelines are used in underground mining in greatly varying embodiments. For stationary laying of such lines in underground passages, the pipes are usually suspended using typical chains on the structure located in the passages. The mechanical loads of such pipelines and their connections are therefore relatively low.
2. Description of Related Art
A device according to the species is known from DE 197 13 202 C1, from the applicant of the present application. A pipe coupling having a screw connection is described therein, which may still be opened easily even after longer intervals and is resistant to the strong atmospheric contamination underground.
In addition, however, there are also regions in underground mining in which high-pressure pipelines must be laid which are subjected to extreme mechanical strains. This particularly applies for use in a longwall. Such longwall lines are attached directly to the bracket of a conveyor, in that the line is suspended below the cable channel for the electrical supply line of disk shearers. Such pipelines are used for the hydraulic supply of the shield-type support in the longwall. The shield-type support is hydraulically controlled in this case and forms a buttress with the conveyor, so that when the shield is tensioned, a region of the conveyor is pressed in the direction of the working face (coal seam) and for retraction, the somewhat reeled-in shields are pulled to the conveyors tensioned by the neighboring shields.
In accordance with the mining of coal, the conveyor runs “snake-like” in the longitudinal direction of the longwall, so that the pipelines mounted on the bracket are subjected to significant bending forces. As individual shields advance, angles arise, which must be absorbed in the elastic range of pipelines. In addition to the bending forces, the pipelines are subjected to changes in length, which may result in the pipeline catching or getting stuck on projecting parts at the connection points of the individual shields. Damage may be caused in this case, which may destroy the pipe connections, the pipeline, or bracket parts.
The above-mentioned loads may not be avoided, however, since the movement of the conveyor is intrinsic to longwall mining, so that the pipe connections present every 2 or 4 m, depending on the pipe length, are pressed against the bracket as they are pushed along and the angling is initiated forcefully. The load must therefore be absorbed by the pipeline and particularly its connection parts.